diff options
| author | Ralf Baechle <ralf@linux-mips.org> | 2006-09-27 20:45:21 -0400 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2007-02-13 17:40:50 -0500 |
| commit | f65e4fa8e0c6022ad58dc88d1b11b12589ed7f9f (patch) | |
| tree | 2405e012e079693e0fcfde9ff981c549d6c68a21 /include/asm-mips/bitops.h | |
| parent | 509cb37e173d4e39cec47238397e91b718730794 (diff) | |
[MIPS] Improve branch prediction in ll/sc atomic operations.
Now that finally all supported versions of binutils have functioning
support for .subsection use .subsection to tweak the branch prediction
I did not modify the R10000 errata variants because it seems unclear if
this will invalidate the workaround which actually relies on the cheesy
prediction of branch likely to cause a misspredict if the sc was
successful.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'include/asm-mips/bitops.h')
| -rw-r--r-- | include/asm-mips/bitops.h | 33 |
1 files changed, 27 insertions, 6 deletions
diff --git a/include/asm-mips/bitops.h b/include/asm-mips/bitops.h index 06445de1324b..06c08228a525 100644 --- a/include/asm-mips/bitops.h +++ b/include/asm-mips/bitops.h | |||
| @@ -68,7 +68,10 @@ static inline void set_bit(unsigned long nr, volatile unsigned long *addr) | |||
| 68 | "1: " __LL "%0, %1 # set_bit \n" | 68 | "1: " __LL "%0, %1 # set_bit \n" |
| 69 | " or %0, %2 \n" | 69 | " or %0, %2 \n" |
| 70 | " " __SC "%0, %1 \n" | 70 | " " __SC "%0, %1 \n" |
| 71 | " beqz %0, 1b \n" | 71 | " beqz %0, 2f \n" |
| 72 | " .subsection 2 \n" | ||
| 73 | "2: b 1b \n" | ||
| 74 | " .previous \n" | ||
| 72 | " .set mips0 \n" | 75 | " .set mips0 \n" |
| 73 | : "=&r" (temp), "=m" (*m) | 76 | : "=&r" (temp), "=m" (*m) |
| 74 | : "ir" (1UL << (nr & SZLONG_MASK)), "m" (*m)); | 77 | : "ir" (1UL << (nr & SZLONG_MASK)), "m" (*m)); |
| @@ -116,7 +119,10 @@ static inline void clear_bit(unsigned long nr, volatile unsigned long *addr) | |||
| 116 | "1: " __LL "%0, %1 # clear_bit \n" | 119 | "1: " __LL "%0, %1 # clear_bit \n" |
| 117 | " and %0, %2 \n" | 120 | " and %0, %2 \n" |
| 118 | " " __SC "%0, %1 \n" | 121 | " " __SC "%0, %1 \n" |
| 119 | " beqz %0, 1b \n" | 122 | " beqz %0, 2f \n" |
| 123 | " .subsection 2 \n" | ||
| 124 | "2: b 1b \n" | ||
| 125 | " .previous \n" | ||
| 120 | " .set mips0 \n" | 126 | " .set mips0 \n" |
| 121 | : "=&r" (temp), "=m" (*m) | 127 | : "=&r" (temp), "=m" (*m) |
| 122 | : "ir" (~(1UL << (nr & SZLONG_MASK))), "m" (*m)); | 128 | : "ir" (~(1UL << (nr & SZLONG_MASK))), "m" (*m)); |
| @@ -166,7 +172,10 @@ static inline void change_bit(unsigned long nr, volatile unsigned long *addr) | |||
| 166 | "1: " __LL "%0, %1 # change_bit \n" | 172 | "1: " __LL "%0, %1 # change_bit \n" |
| 167 | " xor %0, %2 \n" | 173 | " xor %0, %2 \n" |
| 168 | " " __SC "%0, %1 \n" | 174 | " " __SC "%0, %1 \n" |
| 169 | " beqz %0, 1b \n" | 175 | " beqz %0, 2f \n" |
| 176 | " .subsection 2 \n" | ||
| 177 | "2: b 1b \n" | ||
| 178 | " .previous \n" | ||
| 170 | " .set mips0 \n" | 179 | " .set mips0 \n" |
| 171 | : "=&r" (temp), "=m" (*m) | 180 | : "=&r" (temp), "=m" (*m) |
| 172 | : "ir" (1UL << (nr & SZLONG_MASK)), "m" (*m)); | 181 | : "ir" (1UL << (nr & SZLONG_MASK)), "m" (*m)); |
| @@ -222,8 +231,12 @@ static inline int test_and_set_bit(unsigned long nr, | |||
| 222 | "1: " __LL "%0, %1 # test_and_set_bit \n" | 231 | "1: " __LL "%0, %1 # test_and_set_bit \n" |
| 223 | " or %2, %0, %3 \n" | 232 | " or %2, %0, %3 \n" |
| 224 | " " __SC "%2, %1 \n" | 233 | " " __SC "%2, %1 \n" |
| 225 | " beqz %2, 1b \n" | 234 | " beqz %2, 2f \n" |
| 226 | " and %2, %0, %3 \n" | 235 | " and %2, %0, %3 \n" |
| 236 | " .subsection 2 \n" | ||
| 237 | "2: b 1b \n" | ||
| 238 | " nop \n" | ||
| 239 | " .previous \n" | ||
| 227 | " .set pop \n" | 240 | " .set pop \n" |
| 228 | : "=&r" (temp), "=m" (*m), "=&r" (res) | 241 | : "=&r" (temp), "=m" (*m), "=&r" (res) |
| 229 | : "r" (1UL << (nr & SZLONG_MASK)), "m" (*m) | 242 | : "r" (1UL << (nr & SZLONG_MASK)), "m" (*m) |
| @@ -290,8 +303,12 @@ static inline int test_and_clear_bit(unsigned long nr, | |||
| 290 | " or %2, %0, %3 \n" | 303 | " or %2, %0, %3 \n" |
| 291 | " xor %2, %3 \n" | 304 | " xor %2, %3 \n" |
| 292 | " " __SC "%2, %1 \n" | 305 | " " __SC "%2, %1 \n" |
| 293 | " beqz %2, 1b \n" | 306 | " beqz %2, 2f \n" |
| 294 | " and %2, %0, %3 \n" | 307 | " and %2, %0, %3 \n" |
| 308 | " .subsection 2 \n" | ||
| 309 | "2: b 1b \n" | ||
| 310 | " nop \n" | ||
| 311 | " .previous \n" | ||
| 295 | " .set pop \n" | 312 | " .set pop \n" |
| 296 | : "=&r" (temp), "=m" (*m), "=&r" (res) | 313 | : "=&r" (temp), "=m" (*m), "=&r" (res) |
| 297 | : "r" (1UL << (nr & SZLONG_MASK)), "m" (*m) | 314 | : "r" (1UL << (nr & SZLONG_MASK)), "m" (*m) |
| @@ -356,8 +373,12 @@ static inline int test_and_change_bit(unsigned long nr, | |||
| 356 | "1: " __LL "%0, %1 # test_and_change_bit \n" | 373 | "1: " __LL "%0, %1 # test_and_change_bit \n" |
| 357 | " xor %2, %0, %3 \n" | 374 | " xor %2, %0, %3 \n" |
| 358 | " " __SC "\t%2, %1 \n" | 375 | " " __SC "\t%2, %1 \n" |
| 359 | " beqz %2, 1b \n" | 376 | " beqz %2, 2f \n" |
| 360 | " and %2, %0, %3 \n" | 377 | " and %2, %0, %3 \n" |
| 378 | " .subsection 2 \n" | ||
| 379 | "2: b 1b \n" | ||
| 380 | " nop \n" | ||
| 381 | " .previous \n" | ||
| 361 | " .set pop \n" | 382 | " .set pop \n" |
| 362 | : "=&r" (temp), "=m" (*m), "=&r" (res) | 383 | : "=&r" (temp), "=m" (*m), "=&r" (res) |
| 363 | : "r" (1UL << (nr & SZLONG_MASK)), "m" (*m) | 384 | : "r" (1UL << (nr & SZLONG_MASK)), "m" (*m) |